There have been suggested a method of bringing a combustion gas into contact with an amine absorbing liquid, and separating and capturing carbon dioxide in the combustion gas, and there have been suggested various methods of storing the collected carbon dioxide without releasing carbon dioxide to the atmosphere.
In a process that uses the amine absorbing liquid to separate and capture carbon dioxide, an amine compound (hereinafter referred to as “treatment gas entrained amine”) is scattered to the atmosphere together with a decarbonated treatment gas, and is therefore needed to be efficiently captured.